• Title/Summary/Keyword: research instruments

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Comparison of the standards for absorbed dose to water of the IAEA and the KRISS, Korea in accelerator photon beams

  • L. Czap;I.J. Kim;J.I. Park;C.-Y. Yi;Y. Kim;Z. Msimang
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2698-2703
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    • 2024
  • A bilateral comparison was conducted between the International Atomic Energy Agency (IAEA) and the Korea Research Institute of Standards and Science (KRISS) to measure the absorbed dose to water in accelerator photon beams. KRISS served as a linking laboratory to compare the IAEA standard with the key comparison reference value (KCRV) of the BIPM.RI(I)-K6 program, in which KRISS participated in 2017. Two ionization chambers from the IAEA were used as transfer instruments for the comparison. Both laboratories measured the calibration coefficients of these instruments and calculated the ratios. The ratio of the KRISS standard to the KCRV was applied to obtain the degree of equivalence of the IAEA, along with its uncertainty. The largest deviation of the IAEA measurement from the KCRV was 3.4 mGy/Gy, significantly smaller than the expanded uncertainty of 10.7 mGy/Gy (k = 2, 95% level of confidence). This study demonstrates the equivalence of IAEA's measurement standard for accelerator photon beams to other primary standard dosimetry laboratories. It provides evidence for the satisfactory operation of IAEA's quality management system and enhances the international credibility of the IAEA SSDL network, particularly in high-energy accelerator photon beams from linear accelerators.

Preference of undergraduate students after first experience on nickel-titanium endodontic instruments

  • Kwak, Sang Won;Cheung, Gary Shun-Pan;Ha, Jung-Hong;Kim, Sung Kyo;Lee, Hyojin;Kim, Hyeon-Cheol
    • Restorative Dentistry and Endodontics
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    • v.41 no.3
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    • pp.176-181
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    • 2016
  • Objectives: This study aimed to compare two nickel-titanium systems (rotary vs. reciprocating) for their acceptance by undergraduate students who experienced nickel-titanium (NiTi) instruments for the first time. Materials and Methods: Eighty-one sophomore dental students were first taught on manual root canal preparation with stainless-steel files. After that, they were instructed on the use of ProTaper Universal system (PTU, Dentsply Maillefer), then the WaveOne (WO, Dentsply Maillefer). They practiced with each system on 2 extracted molars, before using those files to shape the buccal or mesial canals of additional first molars. A questionnaire was completed after using each file system, seeking students' perception about 'Ease of use', 'Flexibility', 'Cutting-efficiency', 'Screwing-effect', 'Feeling-safety', and 'Instrumentation-time' of the NiTi files, relative to stainless-steel instrumentation, on a 5-point Likert-type scale. They were also requested to indicate their preference between the two systems. Data was compared between groups using t-test, and with Chi-square test for correlation of each perception value with the preferred choice (p = 0.05). Results: Among the 81 students, 55 indicated their preferred file system as WO and 22 as PTU. All scores were greater than 4 (better) for both systems, compared with stainless-steel files, except for 'Screwing-effect' for PTU. The scores for WO in the categories of 'Flexibility', 'Screwing-effect', and 'Feeling-safety' were significantly higher scores than those of PTU. A significant association between the 'Screwing-effect' and students' preference for WO was observed. Conclusions: Novice operators preferred nickel-titanium instruments to stainless-steel, and majority of them opted for reciprocating file instead of continuous rotating system.

Radiological and Clinical Results of Laminectomy and Posterior Stabilization for Severe Thoracolumbar Burst Fracture : Surgical Technique for One-Stage Operation

  • Kim, Myeong-Soo;Eun, Jong-Pil;Park, Jeong-Soo
    • Journal of Korean Neurosurgical Society
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    • v.50 no.3
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    • pp.224-230
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    • 2011
  • Objective : This study aimed to show the possibility of neural canal enlargement and restoration of bony fragments through laminectomy and minimal facetectomy without pediculectomy or an anterior approach, and also to prove the adequacy of posterior stabilization of vertebral deformities after thoracolumbar bursting fracture. Methods : From January 2003 to June 2009, we experienced 45 patients with thoracolumbar burst fractures. All patients enrolled were presented with either a neural canal compromise of more than 40% with a Benzel-Larson Grade of VI, or more than 30% compromise with less than a Benzel-Larson Grade of V. Most important characteristic of our surgical procedure was repositioning retropulsed bone fragments using custom-designed instruments via laminectomy and minimal facetectomy without removing the fractured bone fragments. Beneath the dural sac, these custom-designed instruments could push the retropulsed bone fragments within the neural canal after the decompression and bone fragment repositioning. Results : The mean kyphotic deformities measured preoperatively and at follow-up within 12 months were 17.7 degrees (${\pm}6.4$ degrees) and 9.6 degrees (${\pm}5.2$ degrees), respectively. The mean midsagittal diameter improved from 8.8 mm (${\pm}2.8$ mm) before surgery to 14.2 mm (${\pm}1.6$ mm) at follow-up. The mean traumatic vertebral body height before surgery was 41.3% (${\pm}12.6%$). At follow-up assessment within 12 months, this score showed a statistically significant increase to 68.3% (${\pm}12.8%$). Neurological improvement occurred in all patients. Conclusion : Though controversy exists in the treatment of severe thoracolumbar burst fracture, we achieved effective radiological and clinical results in the cases of burst fractures causing severe canal compromise and spinal deformity by using this novel custom-designed instruments, via posterior approach alone.

Cross-cultural Validation of Instruments Measuring Health Beliefs about Colorectal Cancer Screening among Korean Americans

  • Lee, Shin-Young;Lee, Eunice E.
    • Journal of Korean Academy of Nursing
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    • v.45 no.1
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    • pp.129-138
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    • 2015
  • Purpose: The purpose of this study was to report the instrument modification and validation processes to make existing health belief model scales culturally appropriate for Korean Americans (KAs) regarding colorectal cancer (CRC) screening utilization. Methods: Instrument translation, individual interviews using cognitive interviewing, and expert reviews were conducted during the instrument modification phase, and a pilot test and a cross-sectional survey were conducted during the instrument validation phase. Data analyses of the cross-sectional survey included internal consistency and construct validity using exploratory and confirmatory factor analysis. Results: The main issues identified during the instrument modification phase were (a) cultural and linguistic translation issues and (b) newly developed items reflecting Korean cultural barriers. Cross-sectional survey analyses during the instrument validation phase revealed that all scales demonstrate good internal consistency reliability (Cronbach's alpha=.72~.88). Exploratory factor analysis showed that susceptibility and severity loaded on the same factor, which may indicate a threat variable. Items with low factor loadings in the confirmatory factor analysis may relate to (a) lack of knowledge about fecal occult blood testing and (b) multiple dimensions of the subscales. Conclusion: Methodological, sequential processes of instrument modification and validation, including translation, individual interviews, expert reviews, pilot testing and a cross-sectional survey, were provided in this study. The findings indicate that existing instruments need to be examined for CRC screening research involving KAs.

A Study of Forfaiting Using Aval - Focusing on the "Law of China on Negotiable Instruments" - (어음보증을 이용한 포페이팅거래에 관한 연구 - 중국 어음법을 중심으로 -)

  • LI, Hong-Shu;KIM, Jong-Chill
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.69
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    • pp.239-259
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    • 2016
  • An increasing number of transactions in the bilateral trade between Korea and China rely on collection and remittance, resulting in an increase in exporters' demand for trade financing. Therefore, there is a need to vitalize forfaiting transactions using drafts or promissory notes, which are based on the collections. In the forfaiting transactions, exporters transfer a payment claim to forfaiters on a non-recourse basis through a without recourse endorsement. However, forfaiters do not know importers' creditworthiness and ability to repay drafts or promissory notes; thus, they need a bank aval as a means of credit support. In forfaiting using aval, the drafts or promissory notes are transferred internationally. However, there is no internationally unified law that regulates drafts and promissory notes, and the governing laws related to such drafts and promissory notes do not accept the "principle of party autonomy." Therefore, there is no other choice but to apply the laws of a certain country, in the event of any dispute relating to such drafts or promissory notes. This paper examined forfaiting using aval from the comparative law perspective, focusing on the "Law of China on Negotiable Instruments." The results of this study may to provide businesses involved in international trade with practical guidance and assistance when using forfaiting with aval, especially in trade with China.

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Detecting buried human remains using near-surface geophysical instruments

  • Powell Kathryn
    • Geophysics and Geophysical Exploration
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    • v.7 no.1
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    • pp.88-92
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    • 2004
  • To improve the recovery rate of unlocated buried human remains in forensic investigations, there is scope to evaluate and develop techniques that are applicable to the Australian environment. I established controlled gravesites (comprising shallow buried kangaroos, pigs, and human cadavers) in South Australia, to allow the methodical testing of remote sensing equipment for the purpose of grave detection in forensic investigations. Eight-month-old pig graves are shown to provide more distinct identifying results using ground-penetrating radar when compared to four-year-old kangaroo graves. Two further aspects of this research are presented: information (obtained from a survey) relating to the police use of geophysical instruments for locating buried human remains, and the use of electrical resistivity for locating human remains buried in a coffin. The survey of Australian police jurisdictions, covering the period 1995-2000, showed that police searches for unlocated bodies have not successfully located human remains using any geophysical instruments (such as ground-penetrating radar, magnetometers, or electrical resistivity). Lower resistivity readings were found coincident with the 150-year-old single historical burial in a heavily excavated field, in a situation where its exact location was previously unknown.

Rating Scales for Attention-Deficit Hyperactivity Disorder in Adults (성인기 주의력결핍 과잉행동장애의 평가척도)

  • Kim, Ye-Ni;Jung, Hee-Yeon;Roh, Sung-Won
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.21 no.1
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    • pp.11-16
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    • 2010
  • This review aimed to assist clinicians in the identification and assessment of adult attention-deficit hyperactivity disorder (ADHD) with an emphasis on diagnostic and rating instruments. Pubmed and RISS were utilized to identify relevant studies and critical reviews on the diagnosis and assessment of adult ADHD, published between 1988 and 2010. The Adult ADHD Self-Report Scale-v1.1, the ADHD Rating Scale-IV, the Conners Adult ADHD Rating Scale, and the Current Symptoms Scale have been utilized for self-reporting of current ADHD symptoms. The Brown ADD Rating Scale, the ADHD Rating Scale-IV, the Current Symptoms Scale, and the Conners Adult ADHD Rating Scale have also been evaluated by an observer. The Childhood Symptom Scale and the Wender-Utah Rating Scale have been used for retrospective assessment of childhood ADHD symptoms and the Adult ADHD Investigator Symptom Rating Scale, the Adult Interview, the Brown ADD Diagnostic Form, the Conners adult ADHD diagnostic interview for DSM-IV, and the Wender-Reimherr Interview have been available as comprehensive diagnostic interviews. There is a wide variety of instruments available with respect to adult ADHD. The choice of appropriate instruments is essential for achieving accurate diagnosis and assessment of this disorder.